<!DOCTYPE html>
<html>
  <head>
        <meta charset="utf-8">
        <title>testD3-30-textforce.html</title>
        <script type="text/javascript" src="d3.v3.js"></script>
    <style type="text/css">
    </style>
    </head>
    <body>
    <p>力导向图之带文字</p>
        <script type="text/javascript">
        //(1)链接数组
var links = [
  {source: "Microsoft", target: "Amazon", type: "licensing"    ,weight:1,color:1},
  {source: "Microsoft", target: "HTC", type: "licensing"       ,weight:3,color:4},
  {source: "Samsung", target: "Apple", type: "suit"            ,weight:4,color:6},
  {source: "Motorola", target: "Apple", type: "suit"           ,weight:6,color:65},
  {source: "Nokia", target: "Apple", type: "resolved"          ,weight:3,color:76},
  {source: "HTC", target: "Apple", type: "suit"                ,weight:8,color:879},
  {source: "Kodak", target: "Apple", type: "suit"              ,weight:7,color:989},
  {source: "Microsoft", target: "Barnes & Noble", type: "suit" ,weight:9,color:643},
  {source: "Microsoft", target: "Foxconn", type: "suit"        ,weight:1,color:54},
  {source: "Oracle", target: "Google", type: "suit"            ,weight:3,color:54},
  {source: "Apple", target: "HTC", type: "suit"                ,weight:4,color:45},
  {source: "Microsoft", target: "Inventec", type: "suit"       ,weight:0,color:43},
  {source: "Samsung", target: "Kodak", type: "resolved"        ,weight:8,color:243},
  {source: "LG", target: "Kodak", type: "resolved"             ,weight:1,color:43},
  {source: "RIM", target: "Kodak", type: "suit"                ,weight:5,color:13},
  {source: "Sony", target: "LG", type: "suit"                  ,weight:3,color:351},
  {source: "Kodak", target: "LG", type: "resolved"             ,weight:4,color:1},
  {source: "Apple", target: "Nokia", type: "resolved"          ,weight:1,color:1},
  {source: "Qualcomm", target: "Nokia", type: "resolved"       ,weight:3,color:4},
  {source: "Apple", target: "Motorola", type: "suit"           ,weight:4,color:6},
  {source: "Microsoft", target: "Motorola", type: "suit"       ,weight:6,color:65},
  {source: "Motorola", target: "Microsoft", type: "suit"       ,weight:3,color:76},
  {source: "Huawei", target: "ZTE", type: "suit"               ,weight:8,color:879},
  {source: "Ericsson", target: "ZTE", type: "suit"             ,weight:7,color:989},
  {source: "Kodak", target: "Samsung", type: "resolved"        ,weight:9,color:643},
  {source: "Apple", target: "Samsung", type: "suit"            ,weight:1,color:54},
  {source: "Kodak", target: "RIM", type: "suit"                ,weight:3,color:54},
  {source: "Nokia", target: "Qualcomm", type: "suit"           ,weight:4,color:45}
];

var nodes = {};

//(2)从链接中分离出不同的节点
//一个小问题：节点的weight属性怎么产生的？
links.forEach(function(link) {  //思路就是：在连接中遍历链接，节点数组有了这个链接的源节点就把链接指向这个节点。没有的话把链接上的节点加到链接数组指定名称name属性，并把链接指向这个节点
console.log(nodes);
  link.source = nodes[link.source] //link.sourc就是节点值比如Apple
  || (nodes[link.source] = {name: link.source});//(填加节点数据)

  link.target = nodes[link.target] || (nodes[link.target] = {name: link.target});
});

var width = 960,
    height = 500;

var force = d3.layout.force()
    .nodes(d3.values(nodes))
    .links(links)
    .size([width, height])
    .linkDistance(60)
    .charge(-300)
    .on("tick", tick)
    .start();

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);
//(3)为链接添加线
var link = svg.selectAll(".link")
    .data(force.links())
    .enter().append("line")
    .attr("class", "link");

var colors=d3.scale.category20();

link.style("stroke",function(d){//  设置线的颜色
    return colors(d.color);
})
.style("stroke-width",function(d,i){//设置线的宽度
    return d.weight;
});
//(4)为链接添加节点
var node = svg.selectAll(".node")
    .data(force.nodes())
  .enter().append("g")
    .attr("class", "node")
    .on("mouseover", mouseover)
    .on("mouseout", mouseout)
    .call(force.drag);


//设置圆点的半径，圆点的度越大weight属性值越大，可以对其做一点数学变换
function  radius (d){
if(!d.weight){//节点weight属性没有值初始化为1（一般就是叶子了）
d.weight=1;
}
    return Math.log(d.weight)*10;
}
node.append("circle")
    .attr("r",function(d){  //设置圆点半径
    return radius (d);
 })
.style("fill",function(d){ //设置圆点的颜色
    return colors(d.weight*d.weight*d.weight);
}) ;

node.append("text")
    .attr("x", 12)
    .attr("dy", ".35em")
    .text(function(d) { return d.name; });

function tick() {//打点更新坐标
  link
      .attr("x1", function(d) { return d.source.x; })
      .attr("y1", function(d) { return d.source.y; })
      .attr("x2", function(d) { return d.target.x; })
      .attr("y2", function(d) { return d.target.y; });

  node
      .attr("transform", function(d) {
            return "translate(" + d.x + "," + d.y + ")";
      });
}

function mouseover() {
  d3.select(this).select("circle").transition()
      .duration(750)
      .attr("r", function(d){  //设置圆点半径
    return radius (d)+10;
 }) ;
}

function mouseout() {
  d3.select(this).select("circle").transition()
      .duration(750)
      .attr("r", function(d){  //恢复圆点半径
    return radius (d);
 }) ;
}
        </script>

    </body>
</html>